Do Hyun Joong, a fallen bodybuilding star, now manages a rundown 24-hour gym. Lee Mi Ran, fresh off a breakup, mistakes it for a nightclub and ends up humiliated. Hyun Joong offers to transform her life through intense training, but his brutal honesty drives her away. Still, his words hit a nerve. Can Hyun Joong change heartbroken Mi Ran's life and save the crumbling gym?